An electrical-magnetic proportional pressure control valve is disclosed in DE 196 24 884 A1. This pressure control valve has a recovery channel, configured with a piston between the compression chamber and the discharge connection. The opening and closing of the control valve can be controlled by the servo-control valve. The armature of the solenoid controls the servo-control valve, in order to correspondingly control the opening and closing of the recovery channel. In this manner, movement of the servo-control valve as a result of deviation of the fluid pressure in the compression chamber is prevented, and is not effected by the electric-magnetic force produced by the solenoid.
Undesired control deviations of the control valve can be considerably diminished by this means.
German DE 44 16 279 A1 discloses a magnet valve having an electrically excitable solenoid with an armature guided therein and configured without pressure. A longitudinal channel extends all the way through the armature. Connecting chambers of the magnet valve are separated from one another by a gasket on the armature. Relatively extensive overflow cross-sections or profiles are made available, while avoiding anticipatory control in direct passages.